Chaeles graham



(Model.)

C. GRAHAM.

DECORATION OF POTTERY WAEE.

No. 315,021. Patented Apr. 7, 1885.

N. Pinzas, Phoxhimogpnar. waimngmn. LM;

UNITED STATES CHARLES GRAHAM, OF

` PATENT OFFICE.

BROOKLYN, NEW YORK.

DECORATION OF POTTERY-WARE.

SPECIFICATION forming part of Letters Patent No. 315,021, dated April 7, 1885.

i' Application tiled August 28, i884. (Model.)

To a/ZZ 1,071,071?, t may concern:

Be it known that I, CHARLEs GRAHAM, of Brooklyn, Kings county, in the State of New York, have invented certain new and useful Improvements in the Decoration of Pottery- Ware, of which the following is a specification.

I have discovered that by proper manipulation glazing may loe removed entirely at certain points by a process analogous to the etching of metals, and Without much eating into or affecting the burned clay lying under it. I have successfully applied this in the development of an importantimprovement in the arts.

I takewhite or light cream or other light colored ware and glaze ituniformly with saltglaze, under. conditions which will give a black, chocolate, or other dark shade. I then cover the surface with a ground of wax or analogous matter,which may be the same as is commonly used in etching on copper or steel. I then transfer to the surface from a previously-made drawing or print the outline of the figures to be etched, and remove the ground on the desired points or along the lines which it is desired to bite, and immerse the whole in dilute hydrofluoric acid, using the acid of astrength one part acid and two parts Water. After an exposure to this acid for about ten minutes the article is taken out, washed with water containing ammonia, and the ground being removed with turpentine or by other suitable means the points and lines will appear in white or the light color of the biscuit, while the remaining portions of the surface-glazing will remain unaffected.

Instead of applying the ground over the whole surface at the beginning, I can, vand in working in the large way I propose in many or most cases,to operate as follows: Prepare a plate, which may be a plane plate of copper, glass, or other suitable material having the lines cut or etched deeply therein, and apply y to this platethe ground, preferably for this purpose using asphalt, or a composition of which the asphalt of Trinidad or analogous material is a principal constituent. Then removing, by scraping or otherwise, all the ground except what remains in the lines, I apply dampened paper, and impress by passing it through between the rollers of a plate-printing press. On removing the paper the ground will-lie thereon in the proper lines. I Now, on applying this to the previouslyglazed ware, and pressing gently over the exterior by what is known as rubbing,77 and removing the paper, the ground will lie'on the ware in the required lines. The effect produced by biting will -be the same as that onthe paper. The lines will be dark on white ground.

If it is desired to make the lines white on dark ground, a similar process can be used, making all thelines in the pattern-plate double, so as to in close between them an unaffected line, which will represent the line to be finally produced in white on the darklyglazed ware. rIhe filling with a coating of the asphalt between the bordering ofthe lines thus produced will be applied by hand `after the paper has been removed from the ware.

I will represent the invention as carried out in the manner last described.

The accompanying drawings form a part of this specification.

Figure lis a side view of a stoneware bottle decorated according to my invention. The remaining figures are on a larger scale. Fig. 2 shows a portion covered with the ground, with the desired lines traced or otherwise cut through the ground. Fig. 3 shows the same immersed in acid with the chemical reaction going on. Fig. 4t shows the resulting condition after the operation is completed and the etchingground has been removed. Figs. `5 and 6 represent an intermediate stage of the work. Fig. 5 is a section through the paper after it has received the outlines in asphalt from an engraved plate. (Not represented.) Fig. 6 shows the ware after the asphalt has been transferred thereto from the paper, but before the spaces between the outlines have been lled in by hand.

The thickness of the coating of asphalt or other ground, as also the thickness of the glaze and the depth to which the acid bites, are all exaggerated in the Iigures to show the peculiarities more distinctly.

Similar letters of reference indicate corresponding parts in all the figures where they occur.

A is the cream-colored body of the crockery; B, a dark salt-glaze; C, the ground of waX,

bitumen, or analogous material adapted to resist the action of the acid; D, the acid, and d the bubbles of gas due to the combination of the acid with the material of the glazing. E is the paper.

I believe that I can afterward immerse the Ware in any ordinary glazing to reglaze the Whole surface, including the portions thus exposed. Gare being taken to avoid the running of the two glazings into each other, the effect will be very fine. I have not in my experiments deemed it necessary to regla-ze the ware. I have left the dark glazing asa ground, the light lines clearly depicted on it being sunk to the' extent of the thickness of the glazing and a little more, and the surface of the body thus exposed being left unglazed.

Modifications may be made. I can treat articles of other shapes and designated by other names than the bottle shown. I can employ a body of dark gray or dark red with a glazing of lighter hue. I can vary the character of the glazing within considerable limits. It is only essential that there shall be a marked contrast between the body A and the glaze B, and that the glaze shall be of a character which is attacked and removed by the acid while the body will not be much affected thereby. A slight biting of the acid into the body will not be a serious evil. I have determined by experiment that the operation, if managed with reasonable care, will not materially under-cut the glaze so as to injure the pottery.

Instead of one part anhydrous acid to two parts water, I can succeed well with some ware using considerably more diluted acidsry one part acid to three parts water. The strength of the acid and the time of exposure will vary with different glazes. The operation will be completed sometimes in less than five minutes. Other glazes will require a longer period, even up to an hour.

lines so as to expose the ground in contrast therewith, thereby presenting ornamental or distinguishing figures, substantially as herein specified.

2. The method described of decorating cylindrical and analogous surfaces of pottery by printing the desired figures, With ground adapted to resist the action of acid, transferring the same by paper or analogous flexible material to the surfaces previously glazed, lling by hand between the lines if necessary, and then exposing to acid until the glazing is bitten through at the exposed points, substantially as herein specified.

3. Ceramic ware having a body and glazing of different tints or shades With the glazing removed in ornamental or distinguishing figures, so as to present a body in contrasty therewith, as herein specified.

In testimony whereof I have hereunto set my hand, at New York city, New York, this 23d day of August, 1884, in the presence of two subscribing witnesses.

CHAS. GRAHAM.

Vitnesses:

J. E. RENWEE, v CHARLES R. SEARLE. 

